The code designation of the concentrator is 4RT:C (R--refracting section of a component lens, T--transmitting section of a component lens, and C--concentrating stage lens).
Prior art includes the Conical Split-Image Microscopic Lens, U.S. Pat. No. 4,277,148, by this inventor. This is a microscopic lens which can be used as a beam concentrator. It has a lower component lens which is similar to the lower component lens of the subject disclosure.
Prior art includes also the Conical Beam Concentrator, U.S. Pat. No. 4,333,713, by this inventor. Both the upper and lower component lenses of this concentrator are similar to the same lenses of the subject disclosure .